When to apply weed prevention after overseeding

I have a new customer that I overseeded with a slit seeder 2 weeks ago. I sprayed with Lesco's Three-Way Selective about 2 months ago. The label says not to Reseed no sooner than 3 to 4 weeks after application of the product which is what I followed.

Only problem is she is complaining about weeds still in her yard, mostly clover and poa annua. I believe it will harm the seed if I apply the Three-Way select again this soon after the reseed. I tried to explain to her that it will take about a month for the Three-Way to totally kill all the weeds, which is what I have seen with some varieties. She didnt say it but I dont think she was satisfied and wants some action taken on the weeds.

I guess my question is, is there another product that I don't know about that is safe to apply 2 weeks after overseeding tall fescue that will produce fast results on the weeds.